Usually our kidneys are good at getting rid of excess sodium in the urine. But when problems with this occur, excess sodium enters the bloodstream. This can boost the amount of blood pumped around our body. The increased pressure on our blood vessels and heart raises the risk of stroke, as well as heart and kidney problems.
Lowering your sodium intake will improve your health and reduce your risk of experiencing these problems, largely through the reduction in blood pressure.
One gram of salt contains approximately 400 milligrams of sodium. The maximum daily limit for adults is a little less than six times this figure: 2,300 milligrams of sodium per day.
Children need much less sodium. Limits range from 1,000 milligrams of sodium per day for children aged one to three years, and between 1,400mg to 2,000mg for those aged between four to 13 years.
The sodium chloride (table salt) we add to other foods during cooking or at the table accounts for less than a quarter of sodium intake. A very small amount of sodium is also present in many foods such as milk and meat that contribute only a very small amount to our overall intake.
Most sodium we eat comes from processed and pre-packaged foods. Sodium is commonly added to foods during processing to add flavour, for preservation and as a raising agent (sodium bicarbonate).
The foods that account for the largest proportion of sodium intake in Australian adults (about 25%) include biscuits, cakes, pastries, pies, dumplings, pizza, hamburgers, hot dogs, and pasta and rice mixed dishes.
A few slices of takeaway pizza or a hamburger easily provides around 65% of daily upper limit of consumption, with around 1,500mg sodium.